1. Field of the Invention
The present invention relates to a power supply apparatus, method for controlling the power supply apparatus, and computer-readable storage medium.
2. Description of the Related Art
In recent years, a non-contact charging system in which a power supply apparatus supplies electric power to a power receiving apparatus such as a mobile phone or digital still camera, to which a secondary battery is attached, without any connection via connectors, so as to charge its secondary battery, is known. For example, as disclosed in Japanese Patent Laid-Open No. 11-98706, it is known that such non-contact charging system charges the secondary battery attached to the power receiving apparatus by an induced electromotive force, which is generated on a secondary coil included in the power receiving apparatus due to a magnetic flux change generated by the power supply apparatus including a primary coil.
In such non-contact charging system, when a plurality of power receiving apparatuses exist within a power supply range, the power supply apparatus supplies at the same time electric power to the plurality of power receiving apparatuses. However, secondary batteries attached to this plurality of power receiving apparatuses have various remaining capacities as remaining power amounts depending on their operable time periods. For example, even when the power supply apparatus supplies at the same time electric power to two power receiving apparatus, a secondary battery to be charged in one power receiving apparatus and that to be charged in the other power receiving apparatus suffer remaining capacity variations. For this reason, even when the power supply apparatus supplies at the same time electric power to the plurality of power receiving apparatuses, these power receiving apparatuses include both an apparatus having a large remaining capacity and that having a small remaining capacity.
That is, even when the power supply apparatus supplies at the same time electric power to the plurality of power receiving apparatuses, since the secondary batteries attached to these power receiving apparatuses suffer remaining capacity variations, the operable time periods of the plurality of power receiving apparatuses cannot be made equal to each other.